Global economic output is $80 trillion. There are 100s of millions of scientists, engineers, programmers, technicians in the world. Aside from the ideological complexities, which are probably intractable, it seems like it would be pretty easy to me.

What would it really take to provide basic housing, food, water, clothing, energy, and medicines to 7 billion people? Robotic automation, free / cheap energy, and access to natural resources.

The difference is that the owners of the capital aren't willing to lose on their investments, and it's cheaper to bulldoze and throw away than to give it away or provide work maintaining the communities that these properties exist in/on.